PREHNITE EPIMORPH AFTER CALCITE. ...

Description

PREHNITE EPIMORPH AFTER CALCITE
Malad Quarry, Mumbai, India
One would think that lava flows, being liquids, would be pretty consistently uniform in composition throughout the flow and, as a consequence, the minerals derived from lava flows would be pretty much the same as well. For reasons still unknown, this is clearly not true. In fact it is so untrue that astute collectors can identify specific Quarries by just looking at a specimen. For example, the Lonavala Quarry is noted for its abundance of light green, druzy Prehnite, which often overcoats other minerals - they end up being "sugar-coated". In this case, a sparkling crust of Prehnite has overcoated large and tabular Calcite crystals. Mineralogists refer to such 'overcoated' specimens as 'Epimorphs'. That the Prehnite has taken on the shape of the underlying Calcite can be seen where one of the secondary crystals has a break in it and the Calcite 'core' is clearly visible. Overall, this is an excellent epimorph since most Lonavala Prehnite specimens just coat Laumontite and coated large Calcite blades are quite uncommon. The centerpiece of this specimen is the 4-inch hexagonal blade rising like a distant mountain from a flock of similar, smaller ones. There are traces of the accompanying lava on the back and bottom, but otherwise the picture is all about Prehnite. In excellent condition it measures 6 x 5½ x 4½ inches (15.2 x 14 x 11.4 cm).

Provenance: ex. Ed David Collection
ex. Bob Nowakowski Collection

*Heritage Auctions strives to provide as much information as possible but encourages in-person inspection by bidders. Statements regarding the condition of objects are only for general guidance and should not be relied upon as complete statements of fact, and do not constitute a representation, warranty or assumption of liability by Heritage. Some condition issues may not be noted in the condition report but are apparent in the provided photos which are considered part of the condition report. Please note that we do not de-frame lots estimated at $1,000 or less and may not be able to provide additional details for lots valued under $500. Heritage does not guarantee the condition of frames and shall not be liable for any damage/scratches to frames, glass/acrylic coverings, original boxes, display accessories, or art that has slipped in frames. All lots are sold "AS IS" under the Terms & Conditions of Auction.